Solar activity was at low levels throughout the period. A total of three C-class flares were observed from active regions; a C1/Sf at 24/2256 UTC from Region 1846 (S17, L=056, class/area Cso/210 on 21
Sep), a C1 at 29/0127 UTC from Region 1853 (N19, L=080, class/area Cao/30 on 28 Sep), and a C1/Sf at 29/0525 UTC from Region 1850 (N09, L=036, class/area Dao/140 on 27 Sep). Region 1850 was the most magnetically complex region on the disk during the period, developing a beta-gamma magnetic configuration on 27 Sep. A filament eruption (with an approximate extent of 35 heliographic degrees)
centered near N15W40, was observed on SDO/AIA imagery beginning at 29/2145 UTC, and was associated with a long-duration C1 flare. This event produced an asymmetrial partial-halo CME visibile on LASCO C2/C3 coronagraph imagery. Additional imagery and analysis is required to determine when the coronal mass ejection (CME) is to arrive at Earth.
No proton events were observed at geosynchronous orbit.
The greater than 2 MeV electron flux at geosynchronous orbit was at high to moderate levels on 23 Sep and early 24 Sep, and then decreased to and remained at normal levels for the remainder of the period.
Geomagnetic field activity was at quiet to unsettled levels with an isolated period of active conditions (1200 - 1500 UTC) on 24 Sep with coronal hole high speed stream (CH HSS) effects. The remainder of the period was quiet.
Forecast of Solar and Geomagnetic Activity 30 September - 26 October 2013
Solar activity is expected to be at very low to low levels throughout the outlook period.
NOAA Scale S1 (Minor) solar radiation storm conditions are expected on 30 Sep - 01 Oct due to particle enhancement from the 29 Sep coronal mass ejection (CME). No S1 or greater proton events are
expected for the remainder of the outlook period.
The greater than 2 MeV electron flux at geosynchronous orbit is expected to be at moderate to high levels on 30 Sep - 10 Oct due to combined coronal hole high speed stream (CH HSS) and CME effects.
Normal to moderate levels are expected for the remainder of the outlook period.
Geomagnetic field activity is expected to be at quiet to active levels on 30 Sep, and quiet to unsettled levels on 01 - 02 Oct with CH HSS effects. Quiet to active conditions are expected on 02 - 04 Oct with likely arrival of the 29 Sep CME associated with a filament eruption. Quiet to unsettled conditions are expected on 10 - 11 Oct, 14 - 16 Oct, and 21 Oct, all due to CH HSS effects. The remainder of the period is expected to be at quiet levels, barring any further transient activity.